A MIMO ISAC System for Ultra-Reliable and Low-Latency Communications

TL;DR

This paper introduces a MIMO ISAC system that enhances ultra-reliable low-latency communication by integrating sensing and communication, using a DPC-based approach to optimize rate, reliability, and detection in finite blocklength regimes.

Contribution

It proposes a novel bi-static MIMO ISAC system with a DPC-based technique for improved URLLC and sensing performance, outperforming traditional schemes.

Findings

DPC-based ISAC significantly improves eMBB rates.

The system effectively balances rate, reliability, and detection.

Outperforms power-sharing and time-sharing schemes.

Abstract

In this paper, we propose a bi-static multiple-input multiple-output (MIMO) integrated sensing and communication (ISAC) system to detect the arrival of ultra-reliable and low-latency communication (URLLC) messages and prioritize their delivery. In this system, a dual-function base station (BS) communicates with a user equipment (UE) and a sensing receiver (SR) is deployed to collect echo signals reflected from a target of interest. The BS regularly transmits messages of enhanced mobile broadband (eMBB) services to the UE. During each eMBB transmission, if the SR senses the presence of a target of interest, it immediately triggers the transmission of an additional URLLC message. To reinforce URLLC transmissions, we propose a dirty-paper coding (DPC)-based technique that mitigates the interference of both eMBB and sensing signals. For this system, we formulate the rate-reliability-detection trade-off in the finite blocklength regime by evaluating the communication rate of the eMBB transmissions, the reliability of the URLLC transmissions and the probability of the target detection. Our numerical analysis show that our proposed DPC-based ISAC scheme significantly outperforms power-sharing based ISAC and traditional time-sharing schemes. In particular, it achieves higher eMBB transmission rate while satisfying both URLLC and sensing constraints.